Making of barite concentrates useful in drilling muds



Patented May 25, 1948 MAKING OF BARITE CONCENTRATES USEFUL IN DRILLING MUDS James B. Duke, Lakeland, Fla., assignor to Minerals Separation North American Corporation, New York, N. Y., a corporation of Maryland No Drawing. Application May 12, 1945, Serial No. 593,530

4 Claims. 1

This invention relates to the making of barite concentrates useful in drilling muds.

Barite concentrates which have been produced by froth-flotation, agglomeration table concentration or other methods involving the use of anionic reagents, are largely non-wettable because of the residues of reagents left on the barite particles. In this non-wettable state, such barite concentrates are not satisfactory for use in the making of drilling muds used in the petroleum oil industry because, in the making of the muds, much air is entrained thereby lowering the specific gravity of the muds.

In order to make such concentrates wettable,

it has been customary to subject them to drying and calcining heat treatments which destroy the reagents on the barite particles. The calcining heat treatment is expensive and diflicult to control, since if the temperature to which the concentrates are subjected is too low the reagents on the barite particles are not destroyed, and if the temperature is too high some of the barite is converted into black ash (barium sulphide). By treating the barite concentrates in accordance with the present invention, this expensive and troublesome calcining heat treatment is eliminated.

The reagents left on the barite particles after froth-flotation concentration are the cause also of other difiiculties. For example, these concentrates must be dewatered before drying, and the reagents left on them tend to interfere with proper settling of the concentrates in such dewatering equipment as thickeners, cones, rake classifiers etc., with resulting large overflow losses and high circulating loads which are a source of never-ending trouble in plant operations.

The present invention is the result of the discovery that treatment of barite concentrates (produced by froth-flotation, agglomeration table concentration or other methods involving the use of anionic reagents in an aqueous pulp of the ore) with a strong mineral acid, followed by the washing of the acid-treated concentrates substantially free of acid and slimes, results in such substantially complete removal of the reagents from the barite particles that the operations in thickener tanks, mechanical cones and rake classifiers are substantially free of the dificulties hereinbefore mentioned; and the further discovery that the acid-treated and washed barite concentrates, after being dried and ground to the m nu necessary fineness (usually about -325 mesh) are in a completely wettable state and suitable for use in the making of drilling muds. The economics in plant operation achieved by the invention are important, and the quality of the final barite product is improved.

The invention will be understood from the following description of several examples showing how the wettability of barite flotation concentrates is increased by the use of the invention. In Examples I to IV, the barite concentrates were produced in the usual way by froth-flotation treatment of a barite ore which had been ground to about minus 35 mesh, and subjected to substantial desliming which resulted in getting rid of most of the minus mesh material. The flotation agents employed in these examples were of the usual kind, namely, caustic soda, fuel oil, and red oil (oleic acid) or a material known as "Varlacoid'which is a mixture of fatty and resin acids. In Examples V and VI, the barite concentrates which were treated in accordance with the invention were produced by froth-flotation operations in a commercial barite concentrating plant. The strong mineral acids used in Examples II, IV, V and VI which illustrate the practice of the invention, were sulfuric acid, nitric acid-and hydrochloric acid, and from the success achieved by the use of these acids the conclusion is justified that strong mineral acids generally are satisfactory in practicing the invention.

Example I.W2'thout acid treatment 1321804 Per Cent Per Cent Products Per Cent Distribution Feed 100. 0 6 2 100. 0 Cone 70. 4 93. 5 95. l Mid-3.. 1.3 74.4 1.4 IMid-Z. s l. 5 61. 3 1. 3 Mid-l. 2. 3 32. 2 1. 0 Tail 24.5 3.3 1,2

m w l v trates the non-wettability of barite concentrates produced by the usual froth-flotation methods involving the use of reagents in an aqueous pulp.

of the ore.

Example II .With sulfuric acid treatment In this example, the barite ore was the same as in Example I and the flotation reagents :were

the same; but the final flotation concentrates were agitated at approximately 50% solids .for

about three minutes in an aqueous pulp containing 5.0 lbs. sulfuric acid per ton of solids; after which the. acid-treated barite concentrates were washed substantially free of acid and slimes. The thus treated concentrates were then dewatered and airedried overnight. When a portion of these dried concentrates was submerged in water, approximately 30% I of the concentrates were not wetted by the water and formed agglomerates. When, however, another portion of these same of acid and slimes, were dewatered and air-dried overnight. When a portion of these air-dried concentrates was submerged in water, approximately 98% of the material appeared to be wetted by the water; and, when another portion was ground to minus 325 mesh and submerged in water, all of the material appeared to be wetted by the water, Therefore, this example, like Example H, proves that acid treatment of barite flotation concentrates followed by washing, dryingand fine grinding, produces a material which is satisfactory for use in the making of drilling Example V.-Wz'th nitric acid treatment The purpose of this example is to show that nitric acid, instead of sulfuric acid, may be employed in practicing the invention. The barite flotation concentrates were obtained from a commercial plant engaged in concentrating barite by air-driedconcentrates was ground to approxiacid-treatment of the barite flotation concern trates, followed by washing and fine grinding, produces barite concentrates which are satisfactory for use in the making of drilling muds.

ExampZe.III.Wz'thout acid treatment In this example, the barite ore and the treatments thereof were the same as in Example I, except that 1.0 lb. of Varlacoid, per ton of solids in the ore, was, substituted for the red oil. As

before, the acid-treated'and washed flotation concentrates were air-dried overnight. When a portion of these air-dried concentrates was submerged in water, approximately of the material was. not wetted by the water and formed large agglomerates which it was impossible to wet by stirring. Also, when another portion of the air-dried concentrates was ground to minus 325,.mesh and submerged in water, substantially all of the material appeared to form very small flocs with some of the material as a froth on the surface of the water. As in the case of Example I, this example illustrates the non-wettability of barite flotation concentrates. whichhave not been subjected to treatment to make them wettable.

Example I V.With sulfuric acid treatment In this example, the barite ore was the same as in Example III, and the barite flotation concentrates were produced with the same flotation agents. These barite flotation concentrates were agitated in an aqueous pulp at approximately 50% solids with 5.0 lbs. of sulfuric acid, per ton of solids, for about 3 minutes; after which the concentrates were washed substantially free froth-flotation treatments with the usual reagents. A portion of these barite concentrates was agitated in an aqueous pulp for about three minutes with 14 lbs. of nitric acid per ton of solids; after which the acid-treated concentrates were washed with water until the acid and slimes were substantially removed. The acid-treated and washed concentrates were then dewatered and dried by heat treatment at a fairly low temperature, care being taken not to burn theconcentrates. After the thus dried barite concentrates had cooled, a portion of them was submerged in water; with the result that although approximately 70% of the material was easily wetted, the other 30% was found to be very difficult or impossible to wet; When, however, another portion of the dried barite concentrates was ground to minus 325 mesh and submerged in water, all of it was easily wetted. Thus, this example proves that nitric acid may be satisfactorily used in practicing the invention.

7 3 Example VL-Wz'th hydrochloric acid treatment In this example, as in Example V, thebarite concentrates subjected to treatment according to th'e invention were obtained from a commercial plant engaged in concentrating barite by the usual froth-flotation methods. In this case,=the barite concentrates were agitated in an aqueous pulp with hydrochloric acid in the amount of 14 lbs. per ton of solids in the pulp, and-were then washed substantially free of acid and slimes. This produced barite concentrates which, after drying and fine grinding, were readily wettable and as satisfactory for use in drilling muds as in the cases of the barite concentrates whichwere treated with sulfuric acid or nitric acid as described inExamples l1, IVand V. 7

What is claimed is:

1 The method of treatin barite concentrates which are coated with reagents owing to having been produced by flotation 0r agglomeration methods involving the use of anionic reagents in an aqueous pulpof. the barite ore, to make said barite concentrates wettable and useful in drilling muds, which comprises agitating said concentrates in an aqueous pulp containing a. strong mineral acid selected fromthe group consisting of sulfuric, nitric and hydrochloric acids, washing said acid-treated pulp substantially free of acid and slimes, drying the thus treated barite -concentrates, and grinding said dried concentrates to thefineness required; in drilling muds.

5 2. The method according to claim 1 in which UNITED STATES PATENTS the mineral acid is sulfuric acid. Number Name D ate 3. The method according to claim 1 in which 1,102,873 Chapman et aL July 7, 1914 the mineral and is nitric acid. 1 365 281 Scott Jan 11 1921 4. The method according to claim 1 in which 5 m l i d m 1 1d 1,575,945 Strand Mar. 9, 1926 e mlnera 301d 5 y roc or 0 ac 2 371 292 Hoag Man 13, 1945 JAMES DUKE OTHER REFERENCES Clemmer et al., U, S. Bureau of Mines Report REFERENCES ED of Investigations No. 3239, pages 14 and 15. T1-

tle: Flotation and depression of nonsulphides: The f II Wm references are of r r in the calcite, silica. and silicates, fluorspar, barite, apafile of this patent: tite, and tungsten minerals. 

